New Technique to Recover By-passed Reserves Above Packer Reduces the Completion Cost and Maximizes the Well Production in ONWJ Field, Indonesia.

摘要

This paper will describe the successful application of cementrnpackers in Offshore Northwest Java Sea (ONWJ) field tornrecover by-passed reserves that are located above thernproduction packer. Previously, conventional completionrntechniques required a workover to re-complete these newrnzones. However, due to their marginal reserves or the wellrnstill has good production from existing zones (ex: in dualrncompletion case where long string is still a good producerrnwhile short string is already shut-in), a workover is not a goodrnoption to recover these by-passed zones. A new treatmentrntechnique in ONWJ field, Indonesia, has been developed to recompleternand treat these zones that are located above thernproduction packer without pulling out completion strings.rnIsolation of potential zones is accomplished by cementing inrnthe tubing-casing annulus above the production packer. Therncement above the zone replaces the production packer andrnconventional perforating is then used to complete the well.rnThe advantages of this technique are: inexpensive (no rigrnrequired), no need to wait for the well to achieve economicrnlimit rates before recovering the zones, and - most importantlyrn- it still allows access into the lower completions. On the otherrnhand, the disadvantages of this technique are: less gunrnpenetration (has to penetrate tubing-cement-casing-cementformation),rnand workover/sidetracking below packer isrndifficult to carry out once the packer has been covered byrncement.rnTo date, a total of 7 wells have been reactivated using thisrntechnique to recover the zones/reserves. The jobs have beenrndone successfully in both single and dual completions. The average cost was only 20%-60% of conventional workoverrnjobs and savings of up to US$ 400,000 have been achieved.rnThe production results have also been encouraging. Thesernsuccessful results have brought new opportunities forrnreactivating many more shut-in wells with by-passed reservesrnthat are economically marginal.